A large number of detection systems used sensor wires for detecting the presence of an intruder into a space by the intruder pressing on a sensor wire that may be on or beneath the surface. Various detection systems in prior art patents, U.S. Pat. Nos. 4,527,150; 5,021,766; 4,482,890 and 4,450,434 used optical fibers, coaxial cables, acoustical waves, pressure switches to detect people who may be intruding onto a space.
The present invention is directed to not only detecting the presence of an intruder, but also to determining the direction of travel of the intruder particularly if the intruder is a mobile vehicle traveling at a relatively fast velocity. In the illustrated embodiment of the invention, the intruder is a tank having a velocity typically in the range of 7 meters per second (7 m/s) to 22 m/s and it is desired to provide a tripwire system that is reliable, accurate and is low cost so that it can be deployed in various terrains.